Hot-air furnace.



Patnted May 20, I902.

M. LEE 8:. W. W. BRYAN.

HOT AIR FURNACE.

(Application filed Mar. 22, 1.901.)

4 Sheets-Sheet I.

(No Model.)

Patented May 20, I902.

m. LEE & w. w. BRYAN.

HOT AIR FURNACE.

(Application filed Mar. 22, 1901.3

4 Sheets-Sheet z.

. (No Mt ndel.)

Pa tentgd May 20, I902.

M. LEE,& W. W. BRYAN.

HUT AIR FURNACE. (Application filed Mar. 22, 1901;);

4 Sheets-Sheet 3.

(No Modal.)

No. 700,664. Patent'ed May 20, I902.

' m. LEE & w. w. BRYAN.

HOT AIR FURNACE.

(Application filed Mar. 22, 1901.)

(No Model.) 4 $hee ts-Sheet 4.

li'zydf 1,;

THE "cams PETERS co. PnoToLrri a. vusnmn'rox D. :Y

UNITED STATES ATENT FFICE.

MARION LEE AND WILLIAM WV. BRYAN, OF ANGOLA, INDIANA, ASSIGNORS T O 'WILLIAM M. FANNING, OF ANGOLA, INDIANA.

HOT-AlR-FURNACEQ SPECIFICATION formingpart of Letters Patent No. 700,664, dated May 20, 1902. Application filed March 22, 1901. Serial No- 52,362. (No model.)

To all whom, it may concern:

Be it known that we, MARION LEE and WIL- LIAM W. BRYAN, citizens of the United States, and residents of Angola,in the county of Steuben and State of Indiana, have invented certain new and useful Improvements in Hot-Air Furnaces, of which the following is a specification.

The object of our invention is to provide a hot-air furnace that is easily and cheaply constructed, simple in operation, and that is so constructed as to give the largest possible heating-surface to the'air, and thus get the greatest amount of heat possible from a given amount of fuel.

Referring to the drawings,Figure 1 is a view of our device in elevation, showing the front and one side. Fig. 2 is a view in elevation with the front wall removed. Fig. 3 is a section in elevation on the line w a; of Fig. 2. Fig. 4 is a plan view of the hot-air chamber, showing the tops of the hot-air tubes. Fig. 5 is a transverse section of the combustion-chamber on a line with the smoke-fines. Fig. 6 is a transverse section of the cold-air chamber and ash pit; Fig. 7, a detail viewof'asbestos covering; Figs. 8 and 9, details of the hot-air tubes.

Referring to the drawings, in which like letters of reference denote like parts throughout the several views, A represents the base of the furnace, on which areconstructed the four walls, (indicated by the letter B.) The walls maybe built most economically of brick, though we do not wish to be confined to this construction, as any other suitable material may be utilized, if found more desirable.

The front of the furnace is provided with the usual doors admitting to the fire-pot and ash-pit, and which are provided withthe usual arrangement of drafts.

On the base interior of the four walls is constructed an ash-pit O, having its walls D at a suitable distance from the sideand rear walls of the furnace. Over the ash-pit is set a grate E of any desired construction,and over the space between the ash-pit and sidewalls is set a plate F, made, preferably, of steel that is built into the interior walls of the furnace and the wall forming the ash-pit, as shown at f. The walls D are continued above the grate-E any suitable distance to form the walls Dofthe fire-pot G. Beneath the plate F and surrounding the ash-pit on three sides is the cold-air. chamber H, having any suitable number of cold-air ducts I. At a suitable distance above the fire-pot G a second plate J is provided, made, preferably, of steel, which is set into the Walls B at j and made air-tight. The plate J is also supported by the anchors J, attached thereto in any suitable manner. The space K,included between the plates F and J comprises the combustionch'amber. Near the top of the furnace a third plate L is provided, also made, preferably, of

steel, whichv is set into the walls of the furnace and made air-tight, as indicated at Z, and covered withsand or gravel L. The space M thus formed between the plates J and L is the hot-air chamber.

The plates F and J are perforated to receive the ends of steel tubes-N, arranged around the sides and back of the fire-pot G at suitable distances from each other. The tubes N are made, preferably, larger at the top than atthe bottom, as shown, in order to allow for the expansion of the air in heating and also to offer as large a surface as possible to the heated products of combustion. Near the upper ends of each tube N a metal ringn is riveted, having, anodtwardly-projecting flange n, upon which the plate J rests. The space between the bottom of the plate J and the top of the flange n is filled with fire-clay to insure an air and gas tight fit. It will be seen that the purpose of the flanges n is to assist in supporting theplate J and also prevent the gas escaping fromthe combustion-chamber to thehot-air. chamber.

Aroundthe .bottomsof the tubes N is provided fire-clay Oto insure an air-tight fit and to act as a support for the tubes and the walls of-the fire-pot. Fire-clay P is also provided aroundthe tops of the tubes N, which project through the plate J a suitable distance to prevent the products of combustion enter- 9 ing the hot-air chamber." The fire-clay P has a fine-mesh wirescreenPf through its center to prevent cracking and breaking of the clay in expanding and contracting under the influence of the heat generated in the combus- Lion-chamber K. To further provide against a flow of gas from the combustion-chamber K to the hot-air chamber M, a layer of asbestos Q is provided, cut out at proper places for the tops of the tubes N and the edges turned down and held in the mouth of said tubes by a metal washer q. By means of these details of construction it will be seen that the only communication between the cold-air chamber H and the hot-air chamber M are the tubes N, which, as before described,v pass through the combustion-chamber K.

Around the side and rear walls B is a flue R, the bottom of which is slightly above the level of the top of the plate F and communicates with the combustion chamber K by means of orifices r and with a smoke-stack by means of a flue R. The combined area of the orifices r is exactly equal to the area of the fines R, and the area of the fines R, is exactly equal to the area of the flue B. This is a very important and essential feature, as by this means the products of combustion are forced to be equally distributed throughout the combustion -chamber in order to find egress, and thus all the tubes are subjected to the same amount of heat. In practice it may be found necessary to provide a flue connecting each of the fines R with the smokestack, and we do not, therefore, wish to be confined to the particular construction shown in the drawings. The flues R are provided with openings S, having air-tight doors S, which are intended to be used when cleaning the respective fines.

T represents the ordinary tubes for conveying the heated air to the rooms desired to be heated.

The operation is as follows: Fire is started in the fire-pot G. The smoke and gas,comprising the products of combustion, are carried upward by the Walls of the fire-pot D until they strike the plate J, where they are defiected and pass between the tubes N downward to the orifices r and out through the fiues R and R to the smoke-stack. The cold air enters through the cold-air ducts I, passes through cold-air chamber H and the tubes N, where it is heated, to the hot-air chamber M, from whence it is distributed through the tubes T to the rooms to be heated.

By our construction of fire-pot the products of combustion are forced to the upper part of the combustion-chamber, heating the plate J, and downward, by reason of the draft, to the flue-openings 0, thus heating the full length of the tubes N. By this arrangement the heat is evenly distributed along the tubes, and the danger of melting or breaking the tubes by reason of a direct blast from the fire is dispensed with.

We do not wish to be confined to the exact construction shown and described, as the same may be altered somewhat without departing from the spirit of our invention.

Having thus described our invention, what we claim is 1. In-a hot-air furnace, metal plates set into the walls thereof forming a cold-air chamber, a combustion-chamber and a hot-air chamber, tubes traversing said combustion-chamber having their tops larger in area than their bottoms and extending above the floor of the hot-air chamber, a layer of clay having a wirenetting interposed therein covering the floor of said hot-air chamber to the level of the top of the hot-air tubes, a sheet of asbestos superposed over said clay, and openings cut in said asbestos over each tube having their edges turned down and held in the mouth of said tubes, substantially as shown and described.

2. In a hot-air furnace, metal plates set into the Walls thereof forming a cold-air chamber, a combustion-chamber anda hot-air chamber, tubes traversing said combustion-chamber having their tops larger in area than their bottoms, a sheet of asbestos in said hot-air chamber covering the ends of said tubes,openings cut in said asbestos over the mouth of each tube, the edges of said openings turned down around the mouth of said tubes, and metal washers secured in the mouth of the tube to hold the edges of said openings therein, substantially as shown and described.

3. In a hot-air furnace, metal plates set into the walls thereof forming a cold-air chamber, a combustion-chamber and a hot-air chamber, a fire-pot in the combustion-chamber having vertically-extended walls to carry the products of combustion upward, smoke-fines interior of the side and rear walls and running horizontally therein near the floor of the combustion chamber, and openings into said chamber to draw the products of combustion downward, substantially as shown and de* scribed.

4:. In a hot-air furnace, a cold-air chamber, a hot-air chamber and a combustion-chamber, tubes connecting said cold-air and hotair chambers, asheet of asbestos in said hotair chamber covering the ends of said tubes,-

ICC

openings cut in said asbestos over the mouth of each tube,the edges of said openings turned down and held in the mouth of said tubes, as and for the purposes shown and described.

5. In a hot-air furnace, the combination of a cold-air chamber at the base, an ash-pit therein inclosed on three sides by said cold air chamber, a combustion-chamber contain= ing a firepot having vertically-extended walls, a hot-air chamber over said combustion-chamber, tubes traversing said combustion-chamber for conveying air from the cold to the hot air chamber and heating during transit, said tubes surrounding the fire-pot on three sides and having the upper parts thereof flaring over the fire-pot, and horizontal fines in the side and rear walls of the furnace opposite the base of the combustion-chamber with outlets into said combustion-chamber, substan; tially as shown and described.

6. In a hotair furnace, the combination with a cold-air chamber, a combustion-chamber and a hot-air chamber of horizontal smokeflues in the side and rear walls of the com- In testimony whereof we hereto affix our bkillstion-chamber and situated near the base signatures in the presence of two witnesses. 10 t ereof, and openings from said smoke-fines into the combustion-chamber, the total area g a 5 of the openings in each wall being equal to thearea of the plane through each smoke- Witnesses: flue cut at right angles to its direction, sub- THAD K. MILLER,

stantially as shown and described. EMANUEL KRATZEE. 

